Apparatus for rewinding a spool



Jan. 14, 1969 B. MOUISSIE ET AL APPARATUS FOR REWINDING A SPOOL Filed Nov. 29, 1966 INVENTOR$ B a B M 00/ 55/5 dble e F/ St/IE/Q Mi. A ORNEY United States Patent F 3,421,707 APPARATUS FOR REWINDING A SPOOL Bob Mouissie and Jiirg Fischer, Yverdon, Vaud, Switzerland, assignors to Paillard S.A., Vaud, Switzerland, a company of Switzerland Filed Nov. 29, 1966, Ser. No. 597,651 Claims priority, application Switzerland, Dec. 16, 1965,

17 ,416/ 65 US. Cl. 24255.12 Claims Int. Cl. Gllb /32; Gllb 15/24 ABSTRACT OF THE DISCLOSURE A strip rewinding apparatus including a wheel and intermediate element journalled upon a drive shaft and provided with coupling means locking the intermediate element to the shaft and clutch means regulating the rotary movement of the wheel. Clutch means also actuates rewinding means dependent upon the braking torque as applied to the wheel by the strip.

Arrangements are already known for rewinding the film off a kinematographic projector, which arrangements start automatically said rewinding at the end of the projection of the film. This starting of the rewinding is performed by a lever adapted to move under the action of a loop of film which collapses at the end of the projection by reason of the increased tensioning of the film which is anchored to the hub of the feed spool. During its movement, said lever controls a number of operations such 'as the opening of the film channel and the reversal of the running of the projection. The operation of, such prior arrangements is comparatively slow and of a reduced accuracy. The present invention has for its object to provide an arrangement directly actuated by the modification in the tensioning of the film, instead of being actuated by a loop of the film.

The present invention relates to an arrangement for controlling the rewinding of a strip, tape or film wound off a spool, which arrangement is sensitive to the increase in the tensioning of said strip, tape or film arising at the end of the unwinding of said spool. According to the invention, said improved arrangement includes a wheel driving the strip and a mechanism responding to the torque transmitted to said wheel, which mechanism includes at least one element moving under the control of said torque, so as to act on the means producing the rewinding.

The accompanying drawings illustrate diagrammatically and by way of example a preferred embodiment of an arrangement for rewinding a film wound off a kinematographic projector according to the invention.

In said drawings:

FIG. 1 is an axial cross-sectional view of the arrangement through line II of FIG. 2.

FIG. 2 is a partial endwise view as seen through line IIII of FIG. 1.

The arrangement illustrated includes a shaft 1 driving wheel constituted by two parts 2 and 3. The part 2 is formed by a drum revolving freely on a portion of a reduced diameter of the shaft 1. The periphery of said drum 2 serves as a bearing surface for the film F the perforations of which cooperate with the teeth 4 provided along the periphery of said part 3 which latter part comprises the primary wheel element of the invention.

The drum 2 includes a hub 5 of which one end is threaded so as to engage a coaxial nut 6. The latter holds in position a frusto-conical spring 7 urging against the drum 2 a number of parts including in succession a washer 8, a friction lining 9, an arm 10, a friction lining 11, the disc-shaped part 3 of the wheel and lastly a friction lining 12.

3,421,707 Patented Jan. 14, 1969 On the other hand, the shaft 1 is rigid with a ratchet wheel 13 adapted to couple the shaft with the drum 2 through the agency of a catch 14 pivotally carried at 15 by the drum 2 and subjected to the action of a spring 16 holding said catch in its position of engagement with the ratchet wheel 13. Said drum 2 serves thus as an intermediate element driving the disc-shaped part 3 the teeth 4 of which draw the film F along; said part 3 is also provided with a projection 17 extending, in parallelism with the axis of the shaft, through an arcuate slot 18 formed in the drum 2. The mechanism includes furthermore a support 19 carrying a bell-crank 20 pivotally secured at 21 to said support and subjected to the action of a return spring 22 holding said bell-crank in a position for which it engages the portion of the film illustrated at F lying in proximity with the wheel 2-3. In the absence of any film portion at F, the bell crank 20 rocks under the action of the spring 22 in a direction opposed to the arrow f2 until the book 23 rigid with the said lever abuts against the end 24 of the support 19. When the lever has entered said position, a spring blade 25 rigid with it lies in the path followed by the four teeth 26 provided at the periphery of the drum 2.

As illustrated in FIG. 2, the arm 10 is subjected to the action of a return spring 27 and engages through its outer end the forked end of an arm 28 controlling the rewinding means associated with the projector.

During the projection of a film, the catch 14 engages the ratchet wheel 13 driven along with the shaft 1 in the direction of the arrow f1, as illustrated in FIG. 2. Consequently, the disc-shaped part 3 is carried along together with the drum 2 through the action of the friction lining 12 inserted between said parts 2 and 3. The arm 10 is held fast against the action of its spring 27 in the position illustrated in solid lines in FIG. 2 under the action of the frictional torque exerted on said arm by the linings 9 and 11. Obviously, it is necessary for the torque transmitted by said linings to be larger than the antagonistic torque exerted by the spring 27 on the arm 10.

Thus the disc-shaped part 3 revolves at the same angular speed as the drum 2 which forms an intermediate driving element inserted between said disc-shaped part 3 and the shaft 1.

The end of the film is anchored energetically onto the hub of the wheel. Thus, when the projection of said film is about to finish, the film which is held in position by the feed spool exerts on the disc-shaped part 3 a braking torque which is higher than the torque adapted to be transmitted by the friction lining 12. Consequently, the part 3 is stopped with reference to the shaft 1 which continues revolving and carries along with it the drum 2. The stopping of the disc-shaped part 3 results in that the projection 17 on the latter stops and serves as an abutment for the end of the catch 14. This causes the catch 14 to pivot against the action of the spring 16 and thereby to disengage the ratchet wheel 13. Consequently, the connection between the ratchet wheel 13 and the wheel parts 2 and 3 is cut oflF, so that the wheel becomes loose with reference to its shaft 1.

The spring 27 urges then the released lever 10 out of the position illustrated in solid lines in FIG. 2 into the position illustrated in dot-and-dash lines which causes the wheel to revolve in a direction opposed to the arrow f1, while the lever 10 shifts the arm 28 and makes it enter the position illustrated at 28' in FIG. 2. The arm 28 controls then the means starting the rewinding of the film, which means are not illustrated since they are well-known per se. In particular, said means provide a system for reversing the direction of operation of the motor driving the projector and for releasing the film with reference to the film gate. The film is then rewound at a high speed and drives along with it the wheel 2-3 which is now loose with reference to the shaft 1.

At the end of the rewinding operation, the film moves off the feed spool and its portion F releases the bellcrank 20 which pivots under the action of its spring 22 and this leads to a locking of the drum 2 by reason of the spring blade 25 carried by the bell-crank entering then the path of the teeth 26 on said drum 2.

When it is desired to project another film, the arm 28 of the control means should be returned from the position 28' into the position 28 (FIG. 2) and this may be executed either by hand or automatically if the film to be projected is carried inside a casing adapted to be fitted on the projector. During this return movement of the arm 28, the arm is shifted against the action of its spring 27, while the drum 2 remains braked by the spring blade 25. Consequently, a relative shifting is obtained between the projection 17 on the disc-shaped part 3 and the catch 14 on the part 2 and this relative shifting releases said catch and allows it to reengage the ratchet wheel 13 under the action of the spring 16. At the end of the rewinding operation, the arm 28 when reaching its position illustrated in solid lines actuates, through the agency of a lever mechanism which is not illustrated the bell-crank 20, so as to shift it in the direction illustrated by the arrow f2 and to thus release on the one hand the drum 2 and to free on the other hand the passage for the film F. The film may ten be projected in the same manner as for the film referred to hereinabove, the film passing off the feed spool being carried along by the teeth 4 on the disc-shaped part 3.

Of course, many modifications may be brought to the arrangement disclosed within the scope of the accompanying claims and obviously the rewinding means may be governed by any mechanism sensitive to the torque transmitted by an actuating member to the first feed wheel. Such a mechanism should of course include at least one element the movement of which is controlled by the torque thus transmitted, while the shifting of said element serves for controlling the means ensuring the rewinding of the film. According to an interesting solution of the problem defined hereinabove, the element of the mechanism sensitive to the torque transmitted may be constituted by a mere electric switch the opening or closing of which releases the rewinding means. Obviously, the arrangement sensitive to the transmitted torque may be located at any point of the kinematic chain transmitting movement to the feed wheel, but it is preferable for said mechanism to be located as near as possible said feed wheel. Obviously also the arrangement described is not restricted to its use with a kinematographic projector and may serve for many other purposes such as the control of the rewinding of the magnetic tape of a magnetophone in which case the toothed feed wheel would be replaced by a frictional driving collar.

We claim:

1. In combination with a roll to which one end of a strip shaped material is secured and off and onto which roll said material is adapted to be unwound and rewound and with means adapted to rewind said material onto the roll, the arrangement comprising, a wheel independent of the roll and engaging said strip shaped material through its periphery, means driving said wheel into rotation in the direction of unwinding of the material off its roll, said rotation being braked at the end of the unwinding of the material by the tensioning of the latter, shiftable coupling means disposed between said drive means and said wheel adapted to disconnect same upon braking of said wheel, an element controlling the rewinding means and means inserted between said wheel and said element adapted upon braking of the rotation of said wheel to cause said element to release the operation of said rewinding means.

2. An arrangement as claimed in claim 1, including, a spring urging said element controlling the rewinding means into a position insuring operation of the latter, and wherein said means inserted between said wheel and said element include a frictional clutch through which said element is urged away from last-mentioned position by the rotation of said spring as long as said wheel remains connected with said driving means in the absence of any braking torque.

3. An arrangement as claimed in claim 1, wherein the means driving the wheel into rotation include a shaft coaxial with the wheel and independent thereof, said coupling means including a ratchet wheel rigid with the shaft, an intermediate element coaxial with the shaft and a catch pivotally secured to the intermediate element and adapted to engage the ratchet wheel to ensure the drive of the intermediate element in a direction corresponding to the direction of rotation of the wheel during the unwinding of the material and a friction clutch between the wheel and the intermediate element and adapted to disconnect the latter upon braking of the rotation of the wheel at the end of the unwinding of the material.

4. An arrangement as claimed in claim 1, comprising a spring urging the element controlling the rewinding means into a position ensuring operation of the latter and wherein the means inserted between the wheel and said element include a frictional clutch through which said element is urged away from last-mentioned position by the rotation of the wheel against the action of said spring and wherein the means driving the wheel into rotation include a shaft coaxial with the wheel and independent thereof, said coupling means including a ratchet Wheel rigid with the shaft, an intermediate element coaxial with the shaft and a catch pivotally carried by the intermediate element and adapted to engage the ratchet wheel to ensure the drive of the intermediate element in a direction corresponding to the direction of rotation of the wheel during the unwinding of the material, a friction clutch between the wheel and the intermediate element and adapted to disconnect the latter upon braking of the rotation of the wheel at the end of the unwinding of the material and a coupling between the ratchet wheel and the intermediate element limiting the relative movement between said parts to a predetermined angle.

5. An arrangement as claimed in claim 1, comprising a feeler adapted to engage the edge of the material at a point near the wheel, means urging said feeler against said edge and beyond the location of the latter when no material is present and wherein the means driving the wheel into rotation include a shaft coaxial with the wheel and independent thereof, said coupling means including a ratchet wheel rigid with the shaft, an intermediate element coaxial with the shaft and a catch pivotally carried by the intermediate element and adapted to engage the ratchet wheel to ensure drive of the intermediate element in a direction corresponding to the direction of rotation of the wheel during the unwinding of the material, a friction clutch between the Wheel and the intermediate element and adapted to disconnect the latter upon braking of the rotation of the wheel at the end of the unwinding of the material, and means through which the feeler, when released upon absence of material engaging it, engages the intermediate element to hold the latter angularly fast.

References Cited UNITED STATES PATENTS 3,136,464 6/1964 Schmid 242-55.l3 X

LEONARD D. CHRISTIAN, Primary Examiner. 

